Born in Santa Cruz, California, Radetsky began his ballet studies in the San Francisco Bay Area with Damara Bennett and Ayako Takahashi. At the age of 15, he was invited to study in Moscow at the Bolshoi Academy under world-renowned men's teacher Pytor Pestov. After a year in Russia, he studied on scholarship at the Kirov Academy in Washington, D. C. under Rudolph Kharatian and Andrei Garbouz. He toured with the Kirov Ballet throughout the United States and internationally. He also studied on scholarship at the summer programs of the School of American Ballet, American Ballet Theatre's School of Classical Ballet with Mikhail Baryshnikov, the San Francisco Ballet School and the Bolshoi Ballet Academy in Vail, Colorado.
Radetsky joined American Ballet Theatre as an apprentice in 1995, became a member of the corps de ballet in 1996 and a Soloist in 2003. His repertoire includes the Head Fakir in La Bayadère, Accordionist in The Bright Stream, the third movement in Bruch Violin Concerto No. 1, Her Prince Charming in Cinderella, Boogie Woogie Bugle Boy in Company B, Lankendem and Birbanto in Le Corsaire, Espada and the lead gypsy in Don Quixote, Demetrius in The Dream, the Pastor in Fall River Legend, the second and third sailor in Fancy Free, Hilarion and the peasant pas de deux in Giselle, the pas de deux in Jabula, Gaston in Lady of the Camellias, Lescaut and the Jailer in Manon, Camille in The Merry Widow, His Friend in The Moor's Pavane, the Cavalier and the Nutcracker-Prince and in Kevin McKenzie's The Nutcracker, Iago in Othello, Petrouchka in Petrouchka, the Warrior Chieftain in the Polovtsian Dances from Prince Igor, Rabbit in Rabbit and Rogue, Bernard in Raymonda, the Champion Roper in Rodeo, Paris, Tybalt and Benvolio in Romeo and Juliet, the Bluebird in The Sleeping Beauty, Benno and von Rothbart (Act III) in Swan Lake, Orion in Sylvia, the fourth movement in Symphony in C, Hortensio in The Taming of the Shrew, Thaïs Pas de Deux, the "Guitar" pas de deux from Within You Without You: A Tribute to George Harrison and leading roles in The Brahms-Haydn Variations, C. to C. (Close to Chuck), Clear, Études, Gong, In the Upper Room, The Leaves Are Fading, Symphony #9 and many others. He created leading roles in Aftereffect, From Here On Out, Glow-Stop, Gong, Troika and Thirteen Diversions.
Radetsky has danced the works of acclaimed choreographers such as George Balanchine, Mark Morris, Paul Taylor, Lar Lubovitch, Sir Kenneth MacMillan, Twyla Tharp, Antony Tudor, John Cranko, Agnes de Mille, Jorma Elo, Jerome Robbins, Ann Reinking, Christopher Wheeldon and Jiri Kylian. He is an original member of the troupe "Stiefel and Stars" and has been a frequent guest performer and teacher with ballet companies across the United States and abroad.
In 2000, Radetsky starred as Charlie in the movie Center Stage as well as in pop singer Mandy Moore's music video "I Wanna Be With You" from the Center Stage soundtrack. He has appeared in numerous television and print commercials as well as starring roles in the PBS movie Home at Last and in the NBC television series Midnight Caller. He has written for Newsweek, Dance Magazine, Dance Spirit and World Arts Today.com. He is married to ABT Soloist Stella Abrera.
In September 2008, Radetsky joined Dutch National Ballet as a principal dancer, where his repertoire included Masetto in Don Giovanni, Basilio in Don Quixote, Sanguinic in The Four Temperaments, Albrecht in Giselle and The Son in Prodigal Son.